The present invention refers to a teatcup liner adapted to be mounted in a shell to form a teatcup to be applied to a teat of an animal in accordance with the pre-characterizing portion of claim 1. Such a teatcup liner is disclosed in WO2005/120216.
The invention also refers to a teatcup including a teatcup liner and a shell.
Teatcup liners are typically manufactured in a natural or synthetic rubber material. Rubber materials have many advantages connected to the elastic properties of rubber. These elastic properties are advantageous both during the manufacturing of the teatcup liner and during milking. The teatcup liner formed in a mould can easily be removed from the mould and the core shaping the inner space of the teatcup liner after the vulcanisation. However, the vulcanisation of the rubber requires a significant vulcanisation time before the rubber can be removed from the mould and the core. This is a limiting factor in the manufacturing of teatcup liners. It is desirable to be able to shorten the vulcanisation time. In WO2005/120216 mentioned above it is proposed to manufacture teatcup liners in a thermoformed material, i.e. Thermo Plastic Elastomers, TPE. By using such plastic materials, the manufacturing time needed can be significantly reduced.
However, TPE materials is somewhat less elastic than corresponding rubber materials. This means that when mounting the teatcup liner in a shell to form a teatcup, the force to be applied to the liner for pulling the liner to a proper engaged position in the shell will be rather high with TPE liners. In order to overcome this problem, WO2005/120216 proposes to include a disengageable grip member at the lower end of the teatcup liner. When mounting the teatcup liner, the grip member can be gripped by the operator who then pulls the teatcup liner to a proper position in the shell. However, such a pulling operation has to be performed a large number of times when the liners are to be replaced in many teatcups. It is therefore important that the grip member is a convenient tool which the operator easily may grip and which does not hurt the operator or lead to injures. EP-B-717 927 also discloses a teatcup liner having a terminal portion which can be gripped by the operator for pulling the teatcup liner to a proper position in the shell of the teatcup. The terminal portion can be cut of by means of a knife after the teatcup liner has been mounted in the shell.